The present invention relates to the general art of bridges, and to the particular field of over-filled, pre-cast, reinforced concrete arch bridges.
Frequently, overfilled bridges formed of pre-cast reinforced concrete arch elements are used to support one pathway over a second pathway, which can be a waterway, a traffic route or the like. The terms xe2x80x9coverfilled archxe2x80x9d or xe2x80x9coverfilled bridgexe2x80x9d will be discussed in greater detail below, but in general, an overfilled bridge is a bridge formed of arch elements that rest on the ground or on a foundation and has soil or the like resting thereon to support and stabilize the bridge. The arch elements are usually arcuate in shape to be generally cylindrical in circumferential shape, and in particular a prolate shape; however, other shapes can be used. An example of an overfilled bridge of the present disclosure is disclosed in U.S. Pat. Nos. 3,482,406 and 4,458,457, the disclosures of which are incorporated herein by reference.
Often, the horizontal projections of the two pathways do not intersect at a right angle. As used herein, a xe2x80x9cskewed anglexe2x80x9d is an oblique, or non-right, angle, that is, an angle unequal to 90xc2x0 (xe2x89xa090xc2x0). The skewed angle between the two pathways presents several problems for the bridge designer and the bridge builder, especially if the bridge is formed of pre-cast elements as opposed to cast-in-place concrete which can accommodate the skewed angular relationship of the two pathways.
As shorthand, bridges associated with pathways that are oriented at an oblique angle with respect to each other will sometimes be referred to as xe2x80x9cskewed bridges.xe2x80x9d Elements included in such skewed bridges will be referred to as xe2x80x9cskewed elements.xe2x80x9d Likewise, a bridge associated with pathways that are oriented at a right angle with respect to each other will sometimes be referred to as a xe2x80x9cnon-skewedxe2x80x9d bridge and will include xe2x80x9cnon-skewedxe2x80x9d elements.
Heretofore, bridges associated with skewed pathways have included trapezoidal end arch elements to lengthen the bridge at the ends thereof. However, this solution involves customized arch elements. Customized arch elements create several problems and can be costly from the standpoint of equipment and design. Furthermore, aesthetic considerations may be difficult with such designs.
Still further, such specially shaped elements may be difficult to store resulting in a lack of inventory of such elements by a manufacturer. Accordingly, skewed bridges using customized arch elements may take much longer to erect than non-skewed bridges because the elements must be specially fabricated and stock elements which may be on hand cannot be used. Bridges formed of customized elements may also be more expensive than bridges formed of stock elements.
Due to unusual shapes of customized elements, the design calculations, planning, and considerations may be much more difficult and complex for a skewed bridge than for a non-skewed bridge. Due to the unusual elements required certification from appropriate agencies may be difficult and tortuous to obtain for such customized elements. This further adds to the cost and time associated with skewed bridges using the teaching of the prior art as compared to non-skewed bridges.
A further problem associated with the specially designed arch elements is concerned with the elements associated with the arch elements. For example, a spandrel wall designed to be associated with non-skewed arch elements may not work with an arch element that has been specially designed for a skewed bridge. The same problems are associated with foundations, wing walls, joints and the like. The foundation in particular may have to be specially designed, certified, procured and placed for a skewed bridge using such customized arch elements. In fact, the overfill, itself, may have to be designed specially for a skewed bridge using prior art designs. All of this is costly, both in expense and time, difficult and may require special procedures both in design and in the erection process as well as in the bidding and certification process.
Specially designed arch elements used in skewed bridges may also present aesthetic problems since an element or a portion of an element may extend out of the overfill at one or both ends of the bridge. This extension must be accounted for and the overfill modified accordingly. Such modification may be time consuming and costly.
Yet further problems with specially designed bridge elements are associated with the transportation thereof. Non-standard procedures, routes and equipment may be required to ship specially designed bridge elements from a manufacturer to a bridge site. This can be expensive and time consuming.
Therefore, there is a need for a means and method for erecting an overfilled, pre-cast reinforced concrete bridge associated with two pathways that are oriented at an oblique angle with respect to each other and that is easily designed, certified, fabricated, shipped and erected.
It is a main object of the present invention to provide an overfilled, pre-cast, reinforced concrete arch bridge that supports one pathway over another pathway that is oriented at a skewed angle with respect to the first pathway.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of identical arch elements.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of arch elements each of which is non-skewed.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of arch elements that are pre-cast and are similar to arch elements used in non-skewed bridges.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of arch elements that are not specially designed for a skewed bridge.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of arch elements that are supported on a unitary foundation.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of non-skewed arch elements that are independent of each other.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of non-skewed arch elements that can be used for either a skewed bridge or a non-skewed bridge.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of non-skewed arch elements that uses essentially the same considerations, calculations and procedures as a non-skewed bridge.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of non-skewed arch elements that can include accessories that are the same as a non-skewed bridge.
It is another object of the present invention to provide an overfilled, pre-cast, reinforced concrete skewed arch bridge that is formed of a plurality of non-skewed arch elements that can be formed from easily modified, stock, standard non-skewed arch elements.
These, and other, objects are achieved by a providing a skewed overfilled arch bridge formed of a plurality of pre-cast reinforced concrete non-skewed arch elements. The arch elements rest on a foundation structure that is slightly modified from that design used in connection with a non-skewed bridge, but is still quite simple and all other elements, including spandrel walls, wing walls and the like, can be identical to the corresponding elements used in a non-skewed bridge. Even if the foundation is cast in place, the overall construction of the skewed bridge of the present invention is much simpler than the skewed bridges of the prior art because the arch elements of the skewed bridge of the present invention can be pre-cast in the same manner as the arch elements of non-skewed bridges.
Accordingly, a manufacturer can have a large stock of arch elements whereby arch elements are readily available, shipping is carried out in the known manner, and certification procedures are greatly simplified because the elements have already been certified. Shipping considerations as well as on-site erection procedures can closely follow already known considerations and procedures associated with non-skewed bridges. Thus, the overall process of design, bidding, certification, construction and qualification are essentially identical to the non-skewed bridge processes. Accordingly, costs, times and procedures associated with a skewed bridge are quite predictable and greatly reduced from the situation of skewed bridges erected using customized and/or special elements.